Pull percpu-dtc into release branch
[pandora-kernel.git] / arch / ia64 / mm / init.c
1 /*
2  * Initialize MMU support.
3  *
4  * Copyright (C) 1998-2003 Hewlett-Packard Co
5  *      David Mosberger-Tang <davidm@hpl.hp.com>
6  */
7 #include <linux/kernel.h>
8 #include <linux/init.h>
9
10 #include <linux/bootmem.h>
11 #include <linux/efi.h>
12 #include <linux/elf.h>
13 #include <linux/mm.h>
14 #include <linux/mmzone.h>
15 #include <linux/module.h>
16 #include <linux/personality.h>
17 #include <linux/reboot.h>
18 #include <linux/slab.h>
19 #include <linux/swap.h>
20 #include <linux/proc_fs.h>
21 #include <linux/bitops.h>
22 #include <linux/kexec.h>
23
24 #include <asm/a.out.h>
25 #include <asm/dma.h>
26 #include <asm/ia32.h>
27 #include <asm/io.h>
28 #include <asm/machvec.h>
29 #include <asm/numa.h>
30 #include <asm/patch.h>
31 #include <asm/pgalloc.h>
32 #include <asm/sal.h>
33 #include <asm/sections.h>
34 #include <asm/system.h>
35 #include <asm/tlb.h>
36 #include <asm/uaccess.h>
37 #include <asm/unistd.h>
38 #include <asm/mca.h>
39
40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
41
42 DEFINE_PER_CPU(unsigned long *, __pgtable_quicklist);
43 DEFINE_PER_CPU(long, __pgtable_quicklist_size);
44
45 extern void ia64_tlb_init (void);
46
47 unsigned long MAX_DMA_ADDRESS = PAGE_OFFSET + 0x100000000UL;
48
49 #ifdef CONFIG_VIRTUAL_MEM_MAP
50 unsigned long vmalloc_end = VMALLOC_END_INIT;
51 EXPORT_SYMBOL(vmalloc_end);
52 struct page *vmem_map;
53 EXPORT_SYMBOL(vmem_map);
54 #endif
55
56 struct page *zero_page_memmap_ptr;      /* map entry for zero page */
57 EXPORT_SYMBOL(zero_page_memmap_ptr);
58
59 #define MIN_PGT_PAGES                   25UL
60 #define MAX_PGT_FREES_PER_PASS          16L
61 #define PGT_FRACTION_OF_NODE_MEM        16
62
63 static inline long
64 max_pgt_pages(void)
65 {
66         u64 node_free_pages, max_pgt_pages;
67
68 #ifndef CONFIG_NUMA
69         node_free_pages = nr_free_pages();
70 #else
71         node_free_pages = node_page_state(numa_node_id(), NR_FREE_PAGES);
72 #endif
73         max_pgt_pages = node_free_pages / PGT_FRACTION_OF_NODE_MEM;
74         max_pgt_pages = max(max_pgt_pages, MIN_PGT_PAGES);
75         return max_pgt_pages;
76 }
77
78 static inline long
79 min_pages_to_free(void)
80 {
81         long pages_to_free;
82
83         pages_to_free = pgtable_quicklist_size - max_pgt_pages();
84         pages_to_free = min(pages_to_free, MAX_PGT_FREES_PER_PASS);
85         return pages_to_free;
86 }
87
88 void
89 check_pgt_cache(void)
90 {
91         long pages_to_free;
92
93         if (unlikely(pgtable_quicklist_size <= MIN_PGT_PAGES))
94                 return;
95
96         preempt_disable();
97         while (unlikely((pages_to_free = min_pages_to_free()) > 0)) {
98                 while (pages_to_free--) {
99                         free_page((unsigned long)pgtable_quicklist_alloc());
100                 }
101                 preempt_enable();
102                 preempt_disable();
103         }
104         preempt_enable();
105 }
106
107 void
108 lazy_mmu_prot_update (pte_t pte)
109 {
110         unsigned long addr;
111         struct page *page;
112         unsigned long order;
113
114         if (!pte_exec(pte))
115                 return;                         /* not an executable page... */
116
117         page = pte_page(pte);
118         addr = (unsigned long) page_address(page);
119
120         if (test_bit(PG_arch_1, &page->flags))
121                 return;                         /* i-cache is already coherent with d-cache */
122
123         if (PageCompound(page)) {
124                 order = (unsigned long) (page[1].lru.prev);
125                 flush_icache_range(addr, addr + (1UL << order << PAGE_SHIFT));
126         }
127         else
128                 flush_icache_range(addr, addr + PAGE_SIZE);
129         set_bit(PG_arch_1, &page->flags);       /* mark page as clean */
130 }
131
132 /*
133  * Since DMA is i-cache coherent, any (complete) pages that were written via
134  * DMA can be marked as "clean" so that lazy_mmu_prot_update() doesn't have to
135  * flush them when they get mapped into an executable vm-area.
136  */
137 void
138 dma_mark_clean(void *addr, size_t size)
139 {
140         unsigned long pg_addr, end;
141
142         pg_addr = PAGE_ALIGN((unsigned long) addr);
143         end = (unsigned long) addr + size;
144         while (pg_addr + PAGE_SIZE <= end) {
145                 struct page *page = virt_to_page(pg_addr);
146                 set_bit(PG_arch_1, &page->flags);
147                 pg_addr += PAGE_SIZE;
148         }
149 }
150
151 inline void
152 ia64_set_rbs_bot (void)
153 {
154         unsigned long stack_size = current->signal->rlim[RLIMIT_STACK].rlim_max & -16;
155
156         if (stack_size > MAX_USER_STACK_SIZE)
157                 stack_size = MAX_USER_STACK_SIZE;
158         current->thread.rbs_bot = PAGE_ALIGN(current->mm->start_stack - stack_size);
159 }
160
161 /*
162  * This performs some platform-dependent address space initialization.
163  * On IA-64, we want to setup the VM area for the register backing
164  * store (which grows upwards) and install the gateway page which is
165  * used for signal trampolines, etc.
166  */
167 void
168 ia64_init_addr_space (void)
169 {
170         struct vm_area_struct *vma;
171
172         ia64_set_rbs_bot();
173
174         /*
175          * If we're out of memory and kmem_cache_alloc() returns NULL, we simply ignore
176          * the problem.  When the process attempts to write to the register backing store
177          * for the first time, it will get a SEGFAULT in this case.
178          */
179         vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
180         if (vma) {
181                 vma->vm_mm = current->mm;
182                 vma->vm_start = current->thread.rbs_bot & PAGE_MASK;
183                 vma->vm_end = vma->vm_start + PAGE_SIZE;
184                 vma->vm_page_prot = protection_map[VM_DATA_DEFAULT_FLAGS & 0x7];
185                 vma->vm_flags = VM_DATA_DEFAULT_FLAGS|VM_GROWSUP|VM_ACCOUNT;
186                 down_write(&current->mm->mmap_sem);
187                 if (insert_vm_struct(current->mm, vma)) {
188                         up_write(&current->mm->mmap_sem);
189                         kmem_cache_free(vm_area_cachep, vma);
190                         return;
191                 }
192                 up_write(&current->mm->mmap_sem);
193         }
194
195         /* map NaT-page at address zero to speed up speculative dereferencing of NULL: */
196         if (!(current->personality & MMAP_PAGE_ZERO)) {
197                 vma = kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL);
198                 if (vma) {
199                         vma->vm_mm = current->mm;
200                         vma->vm_end = PAGE_SIZE;
201                         vma->vm_page_prot = __pgprot(pgprot_val(PAGE_READONLY) | _PAGE_MA_NAT);
202                         vma->vm_flags = VM_READ | VM_MAYREAD | VM_IO | VM_RESERVED;
203                         down_write(&current->mm->mmap_sem);
204                         if (insert_vm_struct(current->mm, vma)) {
205                                 up_write(&current->mm->mmap_sem);
206                                 kmem_cache_free(vm_area_cachep, vma);
207                                 return;
208                         }
209                         up_write(&current->mm->mmap_sem);
210                 }
211         }
212 }
213
214 void
215 free_initmem (void)
216 {
217         unsigned long addr, eaddr;
218
219         addr = (unsigned long) ia64_imva(__init_begin);
220         eaddr = (unsigned long) ia64_imva(__init_end);
221         while (addr < eaddr) {
222                 ClearPageReserved(virt_to_page(addr));
223                 init_page_count(virt_to_page(addr));
224                 free_page(addr);
225                 ++totalram_pages;
226                 addr += PAGE_SIZE;
227         }
228         printk(KERN_INFO "Freeing unused kernel memory: %ldkB freed\n",
229                (__init_end - __init_begin) >> 10);
230 }
231
232 void __init
233 free_initrd_mem (unsigned long start, unsigned long end)
234 {
235         struct page *page;
236         /*
237          * EFI uses 4KB pages while the kernel can use 4KB or bigger.
238          * Thus EFI and the kernel may have different page sizes. It is
239          * therefore possible to have the initrd share the same page as
240          * the end of the kernel (given current setup).
241          *
242          * To avoid freeing/using the wrong page (kernel sized) we:
243          *      - align up the beginning of initrd
244          *      - align down the end of initrd
245          *
246          *  |             |
247          *  |=============| a000
248          *  |             |
249          *  |             |
250          *  |             | 9000
251          *  |/////////////|
252          *  |/////////////|
253          *  |=============| 8000
254          *  |///INITRD////|
255          *  |/////////////|
256          *  |/////////////| 7000
257          *  |             |
258          *  |KKKKKKKKKKKKK|
259          *  |=============| 6000
260          *  |KKKKKKKKKKKKK|
261          *  |KKKKKKKKKKKKK|
262          *  K=kernel using 8KB pages
263          *
264          * In this example, we must free page 8000 ONLY. So we must align up
265          * initrd_start and keep initrd_end as is.
266          */
267         start = PAGE_ALIGN(start);
268         end = end & PAGE_MASK;
269
270         if (start < end)
271                 printk(KERN_INFO "Freeing initrd memory: %ldkB freed\n", (end - start) >> 10);
272
273         for (; start < end; start += PAGE_SIZE) {
274                 if (!virt_addr_valid(start))
275                         continue;
276                 page = virt_to_page(start);
277                 ClearPageReserved(page);
278                 init_page_count(page);
279                 free_page(start);
280                 ++totalram_pages;
281         }
282 }
283
284 /*
285  * This installs a clean page in the kernel's page table.
286  */
287 static struct page * __init
288 put_kernel_page (struct page *page, unsigned long address, pgprot_t pgprot)
289 {
290         pgd_t *pgd;
291         pud_t *pud;
292         pmd_t *pmd;
293         pte_t *pte;
294
295         if (!PageReserved(page))
296                 printk(KERN_ERR "put_kernel_page: page at 0x%p not in reserved memory\n",
297                        page_address(page));
298
299         pgd = pgd_offset_k(address);            /* note: this is NOT pgd_offset()! */
300
301         {
302                 pud = pud_alloc(&init_mm, pgd, address);
303                 if (!pud)
304                         goto out;
305                 pmd = pmd_alloc(&init_mm, pud, address);
306                 if (!pmd)
307                         goto out;
308                 pte = pte_alloc_kernel(pmd, address);
309                 if (!pte)
310                         goto out;
311                 if (!pte_none(*pte))
312                         goto out;
313                 set_pte(pte, mk_pte(page, pgprot));
314         }
315   out:
316         /* no need for flush_tlb */
317         return page;
318 }
319
320 static void __init
321 setup_gate (void)
322 {
323         struct page *page;
324
325         /*
326          * Map the gate page twice: once read-only to export the ELF
327          * headers etc. and once execute-only page to enable
328          * privilege-promotion via "epc":
329          */
330         page = virt_to_page(ia64_imva(__start_gate_section));
331         put_kernel_page(page, GATE_ADDR, PAGE_READONLY);
332 #ifdef HAVE_BUGGY_SEGREL
333         page = virt_to_page(ia64_imva(__start_gate_section + PAGE_SIZE));
334         put_kernel_page(page, GATE_ADDR + PAGE_SIZE, PAGE_GATE);
335 #else
336         put_kernel_page(page, GATE_ADDR + PERCPU_PAGE_SIZE, PAGE_GATE);
337         /* Fill in the holes (if any) with read-only zero pages: */
338         {
339                 unsigned long addr;
340
341                 for (addr = GATE_ADDR + PAGE_SIZE;
342                      addr < GATE_ADDR + PERCPU_PAGE_SIZE;
343                      addr += PAGE_SIZE)
344                 {
345                         put_kernel_page(ZERO_PAGE(0), addr,
346                                         PAGE_READONLY);
347                         put_kernel_page(ZERO_PAGE(0), addr + PERCPU_PAGE_SIZE,
348                                         PAGE_READONLY);
349                 }
350         }
351 #endif
352         ia64_patch_gate();
353 }
354
355 void __devinit
356 ia64_mmu_init (void *my_cpu_data)
357 {
358         unsigned long pta, impl_va_bits;
359         extern void __devinit tlb_init (void);
360
361 #ifdef CONFIG_DISABLE_VHPT
362 #       define VHPT_ENABLE_BIT  0
363 #else
364 #       define VHPT_ENABLE_BIT  1
365 #endif
366
367         /*
368          * Check if the virtually mapped linear page table (VMLPT) overlaps with a mapped
369          * address space.  The IA-64 architecture guarantees that at least 50 bits of
370          * virtual address space are implemented but if we pick a large enough page size
371          * (e.g., 64KB), the mapped address space is big enough that it will overlap with
372          * VMLPT.  I assume that once we run on machines big enough to warrant 64KB pages,
373          * IMPL_VA_MSB will be significantly bigger, so this is unlikely to become a
374          * problem in practice.  Alternatively, we could truncate the top of the mapped
375          * address space to not permit mappings that would overlap with the VMLPT.
376          * --davidm 00/12/06
377          */
378 #       define pte_bits                 3
379 #       define mapped_space_bits        (3*(PAGE_SHIFT - pte_bits) + PAGE_SHIFT)
380         /*
381          * The virtual page table has to cover the entire implemented address space within
382          * a region even though not all of this space may be mappable.  The reason for
383          * this is that the Access bit and Dirty bit fault handlers perform
384          * non-speculative accesses to the virtual page table, so the address range of the
385          * virtual page table itself needs to be covered by virtual page table.
386          */
387 #       define vmlpt_bits               (impl_va_bits - PAGE_SHIFT + pte_bits)
388 #       define POW2(n)                  (1ULL << (n))
389
390         impl_va_bits = ffz(~(local_cpu_data->unimpl_va_mask | (7UL << 61)));
391
392         if (impl_va_bits < 51 || impl_va_bits > 61)
393                 panic("CPU has bogus IMPL_VA_MSB value of %lu!\n", impl_va_bits - 1);
394         /*
395          * mapped_space_bits - PAGE_SHIFT is the total number of ptes we need,
396          * which must fit into "vmlpt_bits - pte_bits" slots. Second half of
397          * the test makes sure that our mapped space doesn't overlap the
398          * unimplemented hole in the middle of the region.
399          */
400         if ((mapped_space_bits - PAGE_SHIFT > vmlpt_bits - pte_bits) ||
401             (mapped_space_bits > impl_va_bits - 1))
402                 panic("Cannot build a big enough virtual-linear page table"
403                       " to cover mapped address space.\n"
404                       " Try using a smaller page size.\n");
405
406
407         /* place the VMLPT at the end of each page-table mapped region: */
408         pta = POW2(61) - POW2(vmlpt_bits);
409
410         /*
411          * Set the (virtually mapped linear) page table address.  Bit
412          * 8 selects between the short and long format, bits 2-7 the
413          * size of the table, and bit 0 whether the VHPT walker is
414          * enabled.
415          */
416         ia64_set_pta(pta | (0 << 8) | (vmlpt_bits << 2) | VHPT_ENABLE_BIT);
417
418         ia64_tlb_init();
419
420 #ifdef  CONFIG_HUGETLB_PAGE
421         ia64_set_rr(HPAGE_REGION_BASE, HPAGE_SHIFT << 2);
422         ia64_srlz_d();
423 #endif
424 }
425
426 #ifdef CONFIG_VIRTUAL_MEM_MAP
427 int vmemmap_find_next_valid_pfn(int node, int i)
428 {
429         unsigned long end_address, hole_next_pfn;
430         unsigned long stop_address;
431         pg_data_t *pgdat = NODE_DATA(node);
432
433         end_address = (unsigned long) &vmem_map[pgdat->node_start_pfn + i];
434         end_address = PAGE_ALIGN(end_address);
435
436         stop_address = (unsigned long) &vmem_map[
437                 pgdat->node_start_pfn + pgdat->node_spanned_pages];
438
439         do {
440                 pgd_t *pgd;
441                 pud_t *pud;
442                 pmd_t *pmd;
443                 pte_t *pte;
444
445                 pgd = pgd_offset_k(end_address);
446                 if (pgd_none(*pgd)) {
447                         end_address += PGDIR_SIZE;
448                         continue;
449                 }
450
451                 pud = pud_offset(pgd, end_address);
452                 if (pud_none(*pud)) {
453                         end_address += PUD_SIZE;
454                         continue;
455                 }
456
457                 pmd = pmd_offset(pud, end_address);
458                 if (pmd_none(*pmd)) {
459                         end_address += PMD_SIZE;
460                         continue;
461                 }
462
463                 pte = pte_offset_kernel(pmd, end_address);
464 retry_pte:
465                 if (pte_none(*pte)) {
466                         end_address += PAGE_SIZE;
467                         pte++;
468                         if ((end_address < stop_address) &&
469                             (end_address != ALIGN(end_address, 1UL << PMD_SHIFT)))
470                                 goto retry_pte;
471                         continue;
472                 }
473                 /* Found next valid vmem_map page */
474                 break;
475         } while (end_address < stop_address);
476
477         end_address = min(end_address, stop_address);
478         end_address = end_address - (unsigned long) vmem_map + sizeof(struct page) - 1;
479         hole_next_pfn = end_address / sizeof(struct page);
480         return hole_next_pfn - pgdat->node_start_pfn;
481 }
482
483 int __init
484 create_mem_map_page_table (u64 start, u64 end, void *arg)
485 {
486         unsigned long address, start_page, end_page;
487         struct page *map_start, *map_end;
488         int node;
489         pgd_t *pgd;
490         pud_t *pud;
491         pmd_t *pmd;
492         pte_t *pte;
493
494         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
495         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
496
497         start_page = (unsigned long) map_start & PAGE_MASK;
498         end_page = PAGE_ALIGN((unsigned long) map_end);
499         node = paddr_to_nid(__pa(start));
500
501         for (address = start_page; address < end_page; address += PAGE_SIZE) {
502                 pgd = pgd_offset_k(address);
503                 if (pgd_none(*pgd))
504                         pgd_populate(&init_mm, pgd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
505                 pud = pud_offset(pgd, address);
506
507                 if (pud_none(*pud))
508                         pud_populate(&init_mm, pud, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
509                 pmd = pmd_offset(pud, address);
510
511                 if (pmd_none(*pmd))
512                         pmd_populate_kernel(&init_mm, pmd, alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE));
513                 pte = pte_offset_kernel(pmd, address);
514
515                 if (pte_none(*pte))
516                         set_pte(pte, pfn_pte(__pa(alloc_bootmem_pages_node(NODE_DATA(node), PAGE_SIZE)) >> PAGE_SHIFT,
517                                              PAGE_KERNEL));
518         }
519         return 0;
520 }
521
522 struct memmap_init_callback_data {
523         struct page *start;
524         struct page *end;
525         int nid;
526         unsigned long zone;
527 };
528
529 static int
530 virtual_memmap_init (u64 start, u64 end, void *arg)
531 {
532         struct memmap_init_callback_data *args;
533         struct page *map_start, *map_end;
534
535         args = (struct memmap_init_callback_data *) arg;
536         map_start = vmem_map + (__pa(start) >> PAGE_SHIFT);
537         map_end   = vmem_map + (__pa(end) >> PAGE_SHIFT);
538
539         if (map_start < args->start)
540                 map_start = args->start;
541         if (map_end > args->end)
542                 map_end = args->end;
543
544         /*
545          * We have to initialize "out of bounds" struct page elements that fit completely
546          * on the same pages that were allocated for the "in bounds" elements because they
547          * may be referenced later (and found to be "reserved").
548          */
549         map_start -= ((unsigned long) map_start & (PAGE_SIZE - 1)) / sizeof(struct page);
550         map_end += ((PAGE_ALIGN((unsigned long) map_end) - (unsigned long) map_end)
551                     / sizeof(struct page));
552
553         if (map_start < map_end)
554                 memmap_init_zone((unsigned long)(map_end - map_start),
555                                  args->nid, args->zone, page_to_pfn(map_start),
556                                  MEMMAP_EARLY);
557         return 0;
558 }
559
560 void
561 memmap_init (unsigned long size, int nid, unsigned long zone,
562              unsigned long start_pfn)
563 {
564         if (!vmem_map)
565                 memmap_init_zone(size, nid, zone, start_pfn, MEMMAP_EARLY);
566         else {
567                 struct page *start;
568                 struct memmap_init_callback_data args;
569
570                 start = pfn_to_page(start_pfn);
571                 args.start = start;
572                 args.end = start + size;
573                 args.nid = nid;
574                 args.zone = zone;
575
576                 efi_memmap_walk(virtual_memmap_init, &args);
577         }
578 }
579
580 int
581 ia64_pfn_valid (unsigned long pfn)
582 {
583         char byte;
584         struct page *pg = pfn_to_page(pfn);
585
586         return     (__get_user(byte, (char __user *) pg) == 0)
587                 && ((((u64)pg & PAGE_MASK) == (((u64)(pg + 1) - 1) & PAGE_MASK))
588                         || (__get_user(byte, (char __user *) (pg + 1) - 1) == 0));
589 }
590 EXPORT_SYMBOL(ia64_pfn_valid);
591
592 int __init
593 find_largest_hole (u64 start, u64 end, void *arg)
594 {
595         u64 *max_gap = arg;
596
597         static u64 last_end = PAGE_OFFSET;
598
599         /* NOTE: this algorithm assumes efi memmap table is ordered */
600
601         if (*max_gap < (start - last_end))
602                 *max_gap = start - last_end;
603         last_end = end;
604         return 0;
605 }
606
607 #endif /* CONFIG_VIRTUAL_MEM_MAP */
608
609 int __init
610 register_active_ranges(u64 start, u64 end, void *arg)
611 {
612         int nid = paddr_to_nid(__pa(start));
613
614         if (nid < 0)
615                 nid = 0;
616 #ifdef CONFIG_KEXEC
617         if (start > crashk_res.start && start < crashk_res.end)
618                 start = crashk_res.end;
619         if (end > crashk_res.start && end < crashk_res.end)
620                 end = crashk_res.start;
621 #endif
622
623         if (start < end)
624                 add_active_range(nid, __pa(start) >> PAGE_SHIFT,
625                         __pa(end) >> PAGE_SHIFT);
626         return 0;
627 }
628
629 static int __init
630 count_reserved_pages (u64 start, u64 end, void *arg)
631 {
632         unsigned long num_reserved = 0;
633         unsigned long *count = arg;
634
635         for (; start < end; start += PAGE_SIZE)
636                 if (PageReserved(virt_to_page(start)))
637                         ++num_reserved;
638         *count += num_reserved;
639         return 0;
640 }
641
642 int
643 find_max_min_low_pfn (unsigned long start, unsigned long end, void *arg)
644 {
645         unsigned long pfn_start, pfn_end;
646 #ifdef CONFIG_FLATMEM
647         pfn_start = (PAGE_ALIGN(__pa(start))) >> PAGE_SHIFT;
648         pfn_end = (PAGE_ALIGN(__pa(end - 1))) >> PAGE_SHIFT;
649 #else
650         pfn_start = GRANULEROUNDDOWN(__pa(start)) >> PAGE_SHIFT;
651         pfn_end = GRANULEROUNDUP(__pa(end - 1)) >> PAGE_SHIFT;
652 #endif
653         min_low_pfn = min(min_low_pfn, pfn_start);
654         max_low_pfn = max(max_low_pfn, pfn_end);
655         return 0;
656 }
657
658 /*
659  * Boot command-line option "nolwsys" can be used to disable the use of any light-weight
660  * system call handler.  When this option is in effect, all fsyscalls will end up bubbling
661  * down into the kernel and calling the normal (heavy-weight) syscall handler.  This is
662  * useful for performance testing, but conceivably could also come in handy for debugging
663  * purposes.
664  */
665
666 static int nolwsys __initdata;
667
668 static int __init
669 nolwsys_setup (char *s)
670 {
671         nolwsys = 1;
672         return 1;
673 }
674
675 __setup("nolwsys", nolwsys_setup);
676
677 void __init
678 mem_init (void)
679 {
680         long reserved_pages, codesize, datasize, initsize;
681         pg_data_t *pgdat;
682         int i;
683         static struct kcore_list kcore_mem, kcore_vmem, kcore_kernel;
684
685         BUG_ON(PTRS_PER_PGD * sizeof(pgd_t) != PAGE_SIZE);
686         BUG_ON(PTRS_PER_PMD * sizeof(pmd_t) != PAGE_SIZE);
687         BUG_ON(PTRS_PER_PTE * sizeof(pte_t) != PAGE_SIZE);
688
689 #ifdef CONFIG_PCI
690         /*
691          * This needs to be called _after_ the command line has been parsed but _before_
692          * any drivers that may need the PCI DMA interface are initialized or bootmem has
693          * been freed.
694          */
695         platform_dma_init();
696 #endif
697
698 #ifdef CONFIG_FLATMEM
699         if (!mem_map)
700                 BUG();
701         max_mapnr = max_low_pfn;
702 #endif
703
704         high_memory = __va(max_low_pfn * PAGE_SIZE);
705
706         kclist_add(&kcore_mem, __va(0), max_low_pfn * PAGE_SIZE);
707         kclist_add(&kcore_vmem, (void *)VMALLOC_START, VMALLOC_END-VMALLOC_START);
708         kclist_add(&kcore_kernel, _stext, _end - _stext);
709
710         for_each_online_pgdat(pgdat)
711                 if (pgdat->bdata->node_bootmem_map)
712                         totalram_pages += free_all_bootmem_node(pgdat);
713
714         reserved_pages = 0;
715         efi_memmap_walk(count_reserved_pages, &reserved_pages);
716
717         codesize =  (unsigned long) _etext - (unsigned long) _stext;
718         datasize =  (unsigned long) _edata - (unsigned long) _etext;
719         initsize =  (unsigned long) __init_end - (unsigned long) __init_begin;
720
721         printk(KERN_INFO "Memory: %luk/%luk available (%luk code, %luk reserved, "
722                "%luk data, %luk init)\n", (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
723                num_physpages << (PAGE_SHIFT - 10), codesize >> 10,
724                reserved_pages << (PAGE_SHIFT - 10), datasize >> 10, initsize >> 10);
725
726
727         /*
728          * For fsyscall entrpoints with no light-weight handler, use the ordinary
729          * (heavy-weight) handler, but mark it by setting bit 0, so the fsyscall entry
730          * code can tell them apart.
731          */
732         for (i = 0; i < NR_syscalls; ++i) {
733                 extern unsigned long fsyscall_table[NR_syscalls];
734                 extern unsigned long sys_call_table[NR_syscalls];
735
736                 if (!fsyscall_table[i] || nolwsys)
737                         fsyscall_table[i] = sys_call_table[i] | 1;
738         }
739         setup_gate();
740
741 #ifdef CONFIG_IA32_SUPPORT
742         ia32_mem_init();
743 #endif
744 }
745
746 #ifdef CONFIG_MEMORY_HOTPLUG
747 void online_page(struct page *page)
748 {
749         ClearPageReserved(page);
750         init_page_count(page);
751         __free_page(page);
752         totalram_pages++;
753         num_physpages++;
754 }
755
756 int arch_add_memory(int nid, u64 start, u64 size)
757 {
758         pg_data_t *pgdat;
759         struct zone *zone;
760         unsigned long start_pfn = start >> PAGE_SHIFT;
761         unsigned long nr_pages = size >> PAGE_SHIFT;
762         int ret;
763
764         pgdat = NODE_DATA(nid);
765
766         zone = pgdat->node_zones + ZONE_NORMAL;
767         ret = __add_pages(zone, start_pfn, nr_pages);
768
769         if (ret)
770                 printk("%s: Problem encountered in __add_pages() as ret=%d\n",
771                        __FUNCTION__,  ret);
772
773         return ret;
774 }
775
776 int remove_memory(u64 start, u64 size)
777 {
778         return -EINVAL;
779 }
780 EXPORT_SYMBOL_GPL(remove_memory);
781 #endif